545 research outputs found

    Cambrian-Ordovician Aquifer Sustainability Study Linn and Johnson County Groundwater Protected Area Linn and Johnson County, Iowa

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    The Linn and Johnson County Groundwater Protected Area site (LJCPA) is located in east-central Iowa. Eight water users with nine water use permits are found within the LJCPA that allow withdrawal from the Cambrian-Ordovician (CO) aquifer. Water use permits within the LJCPA include the City of Marion, City of North Liberty, City of Tiffin, City of Coralville, City of Iowa City, Archer Daniels Midland-Cedar Rapids (ADM), IngredionCedar Rapids, the University of Iowa - Oakdale Campus, and the University of Iowa - Water Treatment Plant (UI WTP). The LJCPA is one of two designated groundwater protected areas for the CO aquifer in Iowa.https://ir.uiowa.edu/igs_wrir/1020/thumbnail.jp

    Internal Active Thermal Control System (IATCS) Sodium Bicarbonate/Carbonate Buffer in an Open Aqueous Carbon Dioxide System and Corollary Electrochemical/Chemical Reactions Relative to System pH Changes

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    The International Space Station (ISS) Internal Active Thermal Control System (IATCS) experienced a number of chemical changes driven by system absorption of CO2 which altered the coolants pH. The natural effects of the decrease in pH from approximately 9.2 to less than 8.4 had immediate consequences on system corrosion rates and corrosion product interactions with specified coolant constituents. The alkalinity of the system was increased through the development and implementation of a carbonate/bicarbonate buffer that would increase coolant pH to 9.0 10.0 and maintain pH above 9.0 in the presence of ISS cabin concentrations of CO2 up to twenty times higher than ground concentrations. This paper defines how a carbonate/bicarbonate buffer works in an open carbon dioxide system and summarizes the analyses performed on the buffer for safe and effective application in the on-orbit system. The importance of the relationship between the cabin environment and the IATCS is demonstrated as the dominant factor in understanding the system chemistry and pH trends before and after addition of the carbonate/bicarbonate buffer. The paper also documents the corollary electrochemical and chemical reactions the system has experienced and the rationale for remediation of these effects with the addition of the carbonate/bicarbonate buffer

    The Eos SAR Mission

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    The Eos SAR if a key component of the Eos mission. It is currently being launched on a free flyer in parallel with Eos-A to provide coincident measurements of the Earth's surface over a 15 year time span. This paper provides the latest information on the status of the Eos SAR mission, emphasizes the SAR's role in the overall Eos mission, and compares the Eos SAR under study to the earlier SAR on Eos-B

    ISS Internal Active Thermal Control System (IATCS) Coolant Remediation Project

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    The IATCS coolant has experienced a number of anomalies in the time since the US Lab was first activated on Flight 5A in February 2001. These have included: 1) a decrease in coolant pH, 2) increases in inorganic carbon, 3) a reduction in phosphate buffer concentration, 4) an increase in dissolved nickel and precipitation of nickel salts, and 5) increases in microbial concentration. These anomalies represent some risk to the system, have been implicated in some hardware failures and are suspect in others. The ISS program has conducted extensive investigations of the causes and effects of these anomalies and has developed a comprehensive program to remediate the coolant chemistry of the on-orbit system as well as provide a robust and compatible coolant solution for the hardware yet to be delivered. The remediation steps include changes in the coolant chemistry specification, development of a suite of new antimicrobial additives, and development of devices for the removal of nickel and phosphate ions from the coolant. This paper presents an overview of the anomalies, their known and suspected system effects, their causes, and the actions being taken to remediate the coolant

    ISS Internal Active Thermal Control System (IATCS) Coolant Remediation Project -2006 Update

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    The IATCS coolant has experienced a number of anomalies in the time since the US Lab was first activated on Flight 5A in February 2001. These have included: 1) a decrease in coolant pH, 2) increases in inorganic carbon, 3) a reduction in phosphate concentration, 4) an increase in dissolved nickel and precipitation of nickel salts, and 5) increases in microbial concentration. These anomalies represent some risk to the system, have been implicated in some hardware failures and are suspect in others. The ISS program has conducted extensive investigations of the causes and effects of these anomalies and has developed a comprehensive program to remediate the coolant chemistry of the on-orbit system as well as provide a robust and compatible coolant solution for the hardware yet to be delivered. This paper presents a status of the coolant stability over the past year as well as results from destructive analyses of hardware removed from the on-orbit system and the current approach to coolant remediation

    Mission Design for the Lunar Pallet Lander

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    Due to lighting conditions, the program decided to only fly to the north pole in June 2022 and south pole in December 2022. Starting with the June 2022 landing sites at the north pole, a trajectory scan was run for one landing per day for the latitudes from 85 up to 88 degrees at 0.5 degree increments. Each landing site was at lunar dawn, which determined the landing sites longitude as described in the previous section. The results of the June 2022 scan showed that LPL had the capability to reach a landing site at least once per day for the region examined as see in in Figure 12. There appears to be a correlation between the landing sites altitude and the propellant remaining above the landers FPR, Figure 13. This is most likely due to the >10 km altitude constraint at SRM burnout. This constraint was applied to keep the lander high above the lunar terrain to avoid mountains, but can be relaxed when the full terrain data is added. Figure 12. June 2022 Nominal Usable Propellant Remaining vs Landing Date/time Similarly, the December 2022 landing sites were run showing that LPL was also capable of reaching a landing site at the Moon at least once per day. Figure 14 shows the results of the December scan, however, there were 3 landing sites that LPL could not reach. Two were very low in altitude (-5 and -4 km in altitude), which looking at the altitude trends in Figure 15, indicates that these sites may not be feasible with the current mission design. It may be possible to achieve the low altitude landing sites by lowering the SRM burnout altitude constraint, but that requires detailed terrain modeling, planned for a future phase of the analysis. The third non-reachable landing site is most likely due to an optimization error, as its altitude was high enough, at -2 km, that it should not have been a problem for the lander to arrive there. More analysis is required to verify this observation

    1992: Abilene Christian College Bible Lectures - Full Text

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    CORINTH REVISITED: Studies in I Corinthians Being the Abilene Christian University Annual Bible Lectures 1992 Published by ACU PRESS 1634 Campus Court Abilene, Texas 7960

    Bash2py: A bash to Python translator

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    Abstract—Shell scripting is the primary way for programmers to interact at a high level with operating systems. For decades bash shell scripts have thus been used to accomplish various tasks. But Bash has a counter-intuitive syntax that is not well understood by modern programmers and is no longer adequately supported, making it now difficult to maintain. Bash also suffers from poor performance, memory leakage problems, and limited functionality which make continued dependence on it problematic. At the request of our industrial partner, we therefore developed a source-to-source translator, bash2py, which converts bash scripts into Python. Bash2py leverages the open source bash code, and the internal parser employed by Bash to parse any bash script. However, bash2py re-implements the variable expansion that occurs in Bash to better generate correct Python code. Bash2py correctly converts most Bash into Python, but does require human intervention to handle constructs that cannot easily be automatically translated. In our experiments on real-world open source bash scripts bash2py successfully translates 90 % of the code. Feedback from our industrial partner confirms the usefulness of bash2py in practice

    The Eos SAR Mission

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    The Eos SAR if a key component of the Eos mission. It is currently being launched on a free flyer in parallel with Eos-A to provide coincident measurements of the Earth's surface over a 15 year time span. This paper provides the latest information on the status of the Eos SAR mission, emphasizes the SAR's role in the overall Eos mission, and compares the Eos SAR under study to the earlier SAR on Eos-B
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